Patients with CFS may have a number of comorbidities that worsen their prognosis and quality of life.The more common medical conditions includesicca syndrome, irritable bowel syndrome, autonomicdysfunction,

Studies using the Short Form-36 Health Survey (SF-36)reportthat CFS patients have lower scoreson all physical subscales compared to a healthy sample (70) and other groups of patients, indicatinga marked disability and a reduced functional capacity (13,27,65). Indeed, numerous studies havedemonstrated the significant impact of CFS on patients’ quality of life (1,24,50). However, the impactof the

disease on

the partner, as a caregiver,

hasnotbeen quantified

ormeasured.

The partners of patients with a chronic illness have to cope

with a reduced quality of life(10,54).They may feel disoriented (11), isolated,

and abandoned (32). They may also have an increased riskof injury (26) and increased mortality (3). Headaches, abnormal heart rate (47),

may also bepresent. As for the emotional well-being of the partners, this is largely determined by the type of careneeded for the patients

(73). Partners of patients with sensory-motor impairment are probably moreoptimistic than are partners of patients with not only motor impairment but also sensory-cognitivedeficits (20), as in the case of CFS. The need to combine work outside the home with caring for thepatient who remainsthere

can lead to stress (41), decreased leisure time (51) and feeling tired andunable to cope with the situation (10,34).

This disease of unknownetiology has the characteristics of any chronic illness,

but its effects areheightened by the lack of specific diagnostic tests,

treatments,

and the impact it has on functionalability.

Its impact on thepartner canbe considerable. Thepurposeof this study was to examinetheextent to which there is a relationship between the patients’

functional

capacity and psychologicalaspects of the partners. In the event that such a relationshipis

identified, it will

also be quantified.

METHODS

Participants

The sample comprised a group of 32 female CFS patients and their corresponding 32 partners. The32patients were aged 40.3

±

6.7 years, with a height of 1.62

±

0.06 m and weight of 65.3

±

13.6 kg.All the women met CDC criteria (28) for CFS

and,

in all cases the diagnosis was confirmed byconsensusof

two

physicians.

All patients had to meet the following inclusion criteria:(a)diagnosismade at least one year previously;

(b)age between 25 and 50;and(c)having been in a stablerelationship for at least two years (i.e.,

living together with a partner, sharing financial responsibilitiesand maintaining sexual relations; married status was not required).

Overall, 81.3% were married and18.7% single (Table 1).

The research protocol was approved by the relevant institutional ethicscommittee and written informed consent was obtained from all participants.

3

Measures

Psychological parameters were assessed by administering the following scales and inventories to thepartners:

Interpersonal Reactivity Index

(IRI)

(16,17,46): The Interpersonal Reactivity Indexiscomprised of

28 items (seven items on each of its four dimensions),

and is a measure of dispositional empathy,taking as its starting point the notion that empathy consists of a set of separate but related constructs.

The instrument contains four seven-item subscales,

each tapping a separate facet of empathy. Theperspective taking (PT) scale measures the reported tendency to spontaneously adopt thepsychological point of view of others in everyday life ("I sometimes try to understand my friends betterby imagining how

tendency to experience feelings of sympathy and compassion for unfortunate others ("I often havetender, concerned feelings for people less fortunate than me"). The personal distress (PD) scaledetermined

the tendency to experience distress and discomfort in response to extreme distress inothers ("Being in a tense emotional situation scares me"). The fantasy (FS) scale measured

thetendency to imaginatively transpose oneself into fictional situations ("When I am reading aninteresting story or novel, I imagine how I would feel if the events in the story were happening to me").On all items, higher scores indicated

greater importance of the quality specified.

Dyadic Adjustment Scale

(DAS)

(48,59,60):

The

32-itemDASis

one of the most widely

usedinstruments in studies on couples and families (58). It includes four subscales:(a)dyadic consensus;

isdesigned to measure both anxiety as a stable dimension of personality (trait) and anxiety behavior inthe context of the patient’s current situation (state). The STAI has demonstrated its utility formeasuring trait and state anxiety in patients with fatigue (31,57,66). Higher scores indicate moreanxiety.

All patients and partners who were approached agreed to participate and complete the psychologicaland physiological tests. No subjects dropped out of the study. All spouses agreed to participate butnone came to the Unit in order to finish the tests. Partner tests were therefore done at home duringthe week following the patient’s physical test.

to65%. Subjects wereinstructed not to perform any intensive physical activity during the 72 h prior to testing. All tests wereconducted in the morning after a light breakfast.

The participants were tested on a precalibratedcycle ergometer (Excalibur, Lode, Groningen, The Netherlands). They followed a progressiveexercise schedule which increased in ramp by 20 W every minute up to exhaustion, which was themaximal test. After a recoveryperiod of4

min, they performed a personalized supramaximal test,initially without load. The workload was then increased in ramp every 30 sec

by a load correspondingto the maximal value achieved in the previous test (maximal test), up to exhaustion

production were measured by an automatic gas analysis system (MetasysTR-plus, Brainware SA, La Valette, France) equipped with a pneumotach and making use of a two-way mask (Hans Rudolph, Kansas, USA). Gas and volume calibrations were performed before eachtest, according to the manufacturer’s guidelines. Age-based predicted values for VO2

max werecalculated from regression equations derived from maximal testing in a cohort of healthy sedentarywomen (VO2

The Kolmogorov-Smirnov test was used to establish the normal distribution of the different variables.The correlation between the different psychological test

scores (DAS, STAI and IRI) of partners andthe results of the patients’ exercise test were analysed using the bivariate Pearson correlation test.5

After observing the linear relationship between variables that were statistically significant, multipleregression was applied in order to evaluate the influence of the physical test results of patients thatwere statistically related to scores obtained on the psychological tests completed by partners. Thisinvolvedestimating the coefficients of the linear equation, involving one or more independentvariables (parameters of the patients’ physical test), which best predicted the value of the dependentvariable

The IRI scores ofthepartners revealed that ‘perspective taking’ was closely related to the patients’performance on thephysical test (r

=

0.95, p

<

0.05). Themost influential factorsconsistent of thefollowing: (a)

ERCO2

(respiratory equivalent for

CO2) on the maximal test (-7.71); (b)

FECO2

(fraction

ofCO2

inexpired

air) on the maximal test (-5.75); (c)

ERCO2

on thesupramaximal test (5.41);

and(d)ERO2

(respiratory equivalent for oxygen) on the supramaximal test (-5.00) (Table 4). This important7

interaction showed a strong agreement between the theoretical values derived from the exercise testand the actual observed ones (Figure 1). The ‘fantasy’ score of partners showed a statisticallysignificant relationship with some of the values observed during the physical test (r

The DAS total score of partners was related to the results obtained bythepatients on the physicaltest (r

=

0.813, p

<

0.05), the most influential factors being FECO2

on the

supramaximal test (-1.48),FEO2

(fraction

ofO2

inexpired

air) at rest (1.40), ERCO2

on the supramaximal test (-1.09), and FECO2

8

at rest (1.03) (Table 4). On the STAI, state anxiety (r

=

0.596, p

=

0.036) showed a dependence onthe patient’s functional capacity, it being related only to the test at rest and the test duration (-0.39)(Table 4).

DISCUSSION

This studyindicatesthat the functional capacity

as well as the cardiovascular and ventilatoryresponses to exercise of female CFS patients, assessed by a maximal exercise test, has a clearinfluence on the scores obtained by their partners on psychological tests (IRI, DAS and STAI).

The physical test with cardiovascular and ventilatory monitoring assessed

the maximum peak oxygenconsumption, which is considered a reference value for determining the functional capacity of a givenpatient. Previous studies have showna decrease inadaptations to submaximal efforts (23), with adecline in maximal aerobic power in patients with CFS (30, 63), even to 50% of that observed in thereference population. This was the case of the 32 female patients inthe presentstudy. A reducedfunctional capacityhas

a direct impact on the possibility of performing usual daily activities. In thegroup studied the maximal effort achieved could be quantified as 3-4 METS, which suggests thatthese patients would require the involvement of the family network and, specifically, of the partner.However, no CFS research has yet assessed the possible effects of the patient’s functional capacity,as measured by a physical test, on the couple relationship.

Indeed, the relevance of the couple has rarely been studied in the literature on CFS, although it hasbeen shown in other chronic diseases

that when a patient’s pathology is associated with fatigue, theimpact on partners’ personal and social lives is high (2). Most CFS patients show greater dependencein practical daily aspects, especially with respect to their family network (42). However,

whilethepatients’ own reactions to their symptoms have been recognized and studied in the context of CFS(18,42), the beliefs and responses of relatives, as well as the perception and reaction of the patienthas received little attention.

The last twodecades of psychophysiology research in couples have produced resultsthatindicate

a

dissatisfaction(and even divorce)

associated with broad-based patterns of autonomic reactivity (e.g.,

increased electrodermal response and heart rate) during marital interactions. This discovery, bypioneers including John Gottman (1993;22), Robert Levenson and colleagues (1994;38),

and others(25,56), have led the field of psychology to two provocative conclusions: (a) Physical andpsychological well-being are much morerelated than previously thought; and (b) Interpersonalrelationships are important in the context of physical and psychological health in adults.

A central component of this model is the notion that interpersonal (i.e.,satisfaction with the partner)and

intrapersonal (i.e.,personality) characteristics play a role in the gradation of psychophysiologicalreactivity, which has long-term implications for physical health (35,53). Several prospectivelongitudinal studies suggest that marital stress is related

to the results of self-reported health. One ofthe most extensive investigations assessed the marital quality and symptoms of illness in 364 wivesand husbands over a period of four years (72). Participants with higher initial levels of marital qualityreported fewer symptoms of physical illness at baseline. Moreover, improvements in marital qualityduring the four-year period were accompanied by fewer self-reports of symptoms of physical illness.Among 174 patients with renal disease being treated with haemodialysis, higher dyadic satisfactionwas associated with a 29% reduction in mortality risk, while lower satisfaction in the relationship wasassociated with a 46% higher risk of mortality over a three-year follow-up period (36).

9

In the present study the IRI results showed a direct relationship between various physiologicalparameters and the ‘perspective taking’ subscale (as stated above, this subscale measures thereported tendency to spontaneously adopt the psychological point of view of others in everyday life,for example, between the couple). This relationship was observed for the values obtained on both themaximal and supramaximal tests. The most influential factors during the maximal test were theERCO2

and FECO2. It seemsthat a less effective ventilatory response regarding the CO2

eliminationwithrespecttoventilation during exercise is associated with a higher ‘perspective taking’ score. Oneexplanation for this could be that repeated situations in which this adaptation

worsens would lead thepartner to show increased ‘perspective taking’ (i.e.,

involvement) as regarding

the patient’s pathology.

The relationship was different for the supramaximal test. In this case, during a short-term effort, lowerventilatory response for CO2

eliminationwithrespecttoventilation was

associated with lower scoreson perspective taking

(PT). A possible explanation here could be that the more the patient verbalizesher physical symptoms the more perspective taking is shown by the partner. Thus, the partner, in anattempt to understand his wife, could have an added source of stress, especially in relation to patientswho are prone to catastrophizing(or excessively magnifying)

in verbal exchanges about their overallhealth. Catastrophizing pain, marital dissatisfaction,

and depression are important factors that affectthe perception of the partner’s responses to pain (6,64). By contrast, in relation to patients with betterfunctional adaptation, partners would show less perspective taking

and less stress. Other authorshave shown that socialstressors can determine the magnitude of physiological activation

(8).Tobeand hiscolleagues

demonstrated that psychosocial factors may influence the development of earlyhypertension in a study of 248 males and females (67).Similar findings were reported in a childpopulation, where interpersonal stress was reduced as a result of exercise and an improvement infunctional capacity (52).

The relationship between the physical test parameters and the results observed on the IRI subscaleis very strong and shows a very low dispersion (Figure 1). This finding is even more striking if oneconsiders that the researchers who conducted the psychological examination did so at a differenttime to the physical test, that the physical test was carried out by different researchers, and that thoseresponsible for the final evaluation of the results had no direct contact with patients or their partners.This approach would seem to ensure the consistency of the results. Although chronic fatigue isheterogeneous and complex in terms of its clinical manifestations, the fact that the test wasperformed under strict methodological and repetitive conditions allowed us to obtain consistent andvalid results which could then be subsequently evaluatedin

regardstothe relationship to the findingsobtained from the partners’ psychological tests.

The DAS also showed a relationship with functional assessment, in this case with physiologicalvalues during rest and under supramaximal effort. On the supramaximal test, higher ERCO2

andFECO2

were associated with lower scores on the DAS. It seems reasonable to suppose that theinfluence between the DAS and functional capacity could work in both directions. Better functioning inthe couple could lead to more appropriate ventilatory adaptation at rest, and also in the supramaximaltest performed after a maximum effort.

To summarize, the present study hasdemonstrated

the importance of the interaction between thesymptoms of the CFS patient, specifically her functional capacity, and her partner. The sample of 32couples is larger than that used in many studies and the quantificationof functional capacity hasenabled us to determine more rigorously its relationship to psychological aspects of partners. In thiscontext, it should be acknowledged that just as functional capacity could have an impact on thecouple. On a practical level,targeted therapies should therefore be introduced to enhance theseaspects in the couple and help partners to provide better support and care to patients. Over the past10

30 years, dozens of clinical trials have demonstrated the effectiveness of couple therapy in improvingpartner satisfaction (4,15). Although these studies cannot be simply extrapolated to the context of afamily with a CFS patient, they may suggest ways of helping couples to optimize the rate of spousesupport and improve the quality of life

of both patients and partners.

Figure 1. Relationship for the ‘perspective taking’ (PT) scale (Interpersonal Reactivity Index, IRI) between theobserved score in the partners and the theoretical values from the physical test data of the patients.

11

However, despite

the promising findings in terms of an interaction between physiological aspects andmarital satisfaction, a number of limitations should be taken into account. First, unhappy couples areless likely to participate voluntarily in research projects than are those who are more satisfied withtheir spouse (9). In addition, poor marital functioning may be related to the most damaging healthhabits (35), such as an excessive use of alcohol and smoking, both of which may confound thephysiological

measures (33).

CONCLUSION

In conclusion, it appears that thefunctional capacity as well as the cardiovascular and ventilatoryresponsesto exercise of patients with CFS, as assessed by a maximal physical test, has a directeffect on some psychological characteristics of thepartner.

In light of these findings,

it would beinteresting to target an intervention at patients to see whether improvements in functional capacitywould have a quick and positive impact on partners. Conversely, research should examine whetheran improvement in the psychological aspects of the couple might boost the functional capacity ofpatients, as measured by their